driver.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

import javax.swing.JFrame;

/** Driver for cake cutting  (Figures 9.9, 9.10, 9.12, 9.13, and 9.18)
 *  Author: David D. Riley
 *  Date: January, 2005
 */
public class Driver  {
    private JFrame  window;
    private Cake theCake;
    private CakeButton sliceButton;

	/**	post:	window is created at (10, 10) with width and height of 400
	 *				and  sliceButton is added to window
	 *				and  theCake is constructed as a CircularCake object   
	 */
    public Driver()  {
		window = new JFrame("Cake Cutter");
		window.setBounds(10, 10, 400, 500);
		window.setVisible(true);
		window.setLayout(null);
		theCake = new CircularCake(100, 100, 200);
		window.add( theCake, 0 );
		sliceButton = new CakeButton( 75, 5, this);
		window.add( sliceButton, 0 );
		window.repaint();
    }
    
	/**	pre:	theCake != null  <br>
     *		post:	theCake@pre is removed from window
	 *  			and  a new theCake is constructed & placed on window
	 *			 	(The new cake has a 50-50 chance of being circular 
	 *				or rectangular.
	 */
	public  void  cutTheCake()   {
		window.remove(theCake);
    	if (Math.random() > 0.5)   {
			theCake = new CircularCake(100, 100, (int)(Math.random()*200+1));
    	} else {
    		theCake = new RectangularCake(100, 150, 200, (int)(Math.random()*300+1));
    	}
    	window.add( theCake, 0 );
		window.repaint();
    }
}